Iron Uptake in Salmonella typhimurium: Utilization of Exogenous Siderochromes as Iron Carriers

AUTOR(ES)

Luckey, Mary

RESUMO

Aerobic microorganisms have evolved a variety of siderochromes, special ligands which can dissolve insoluble ferric iron and facilitate its transport into the cell. We have found that enb mutants of Salmonella typhimurium blocked in the biosynthesis of enterobactin (its natural iron carrier) are able to utilize siderochromes of different types made by other microorganisms as iron carriers. The antibiotic albomycin δ2 was used to select mutants defective in ferrichrome-mediated iron uptake. Twelve classes of albomycin-resistant mutants, named sid, were defined on the basis of their growth responses to other siderochromes. Most of these classes have genetic lesions in loci that are cotransduced with panC (represented at 9 min on the genetic map). The locus designated sidJ is cotransduced with enb, whereas sidK and sidL are linked with neither panC nor enb. Genetic and physiological data indicate that S. typhimurium has several transport systems of high specificity for a variety of siderochromes produced by other microorganisms.

Documentos Relacionados

• Iron Transport in Salmonella typhimurium: Mutants Blocked in the Biosynthesis of Enterobactin
• Fur regulon of Salmonella typhimurium: identification of new iron-regulated genes.
• Regulation of proline utilization in Salmonella typhimurium: a membrane-associated dehydrogenase binds DNA in vitro.
• Propanediol utilization genes (pdu) of Salmonella typhimurium: three genes for the propanediol dehydratase.
• Regulation of proline utilization in Salmonella typhimurium: characterization of put::Mu d(Ap, lac) operon fusions.